(PERT) A method used to size a software product and calculate the Standard Deviation (SD) for risk assessment. The PERT equation (beta distribution) estimates the Equivalent Delivered Source Instructions (EDSIs) and the SD based on the analyst' s estimates of the lowest pOSsible size, the mOSt likely size, and the highest pOSsible size of each computer program component (CPC). (1996-05-29)